wsevent.c revision 1.5
1/* $OpenBSD: wsevent.c,v 1.5 2005/11/21 18:16:45 millert Exp $ */
2/* $NetBSD: wsevent.c,v 1.16 2003/08/07 16:31:29 agc Exp $ */
3
4/*
5 * Copyright (c) 1996, 1997 Christopher G. Demetriou.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *      This product includes software developed by Christopher G. Demetriou
18 *	for the NetBSD Project.
19 * 4. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35
36/*
37 * Copyright (c) 1992, 1993
38 *	The Regents of the University of California.  All rights reserved.
39 *
40 * This software was developed by the Computer Systems Engineering group
41 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
42 * contributed to Berkeley.
43 *
44 * All advertising materials mentioning features or use of this software
45 * must display the following acknowledgement:
46 *	This product includes software developed by the University of
47 *	California, Lawrence Berkeley Laboratory.
48 *
49 * Redistribution and use in source and binary forms, with or without
50 * modification, are permitted provided that the following conditions
51 * are met:
52 * 1. Redistributions of source code must retain the above copyright
53 *    notice, this list of conditions and the following disclaimer.
54 * 2. Redistributions in binary form must reproduce the above copyright
55 *    notice, this list of conditions and the following disclaimer in the
56 *    documentation and/or other materials provided with the distribution.
57 * 3. Neither the name of the University nor the names of its contributors
58 *    may be used to endorse or promote products derived from this software
59 *    without specific prior written permission.
60 *
61 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71 * SUCH DAMAGE.
72 *
73 *	@(#)event.c	8.1 (Berkeley) 6/11/93
74 */
75
76/*
77 * Internal "wscons_event" queue interface for the keyboard and mouse drivers.
78 */
79
80#include <sys/param.h>
81#include <sys/fcntl.h>
82#include <sys/malloc.h>
83#include <sys/proc.h>
84#include <sys/systm.h>
85#include <sys/vnode.h>
86#include <sys/selinfo.h>
87#include <sys/poll.h>
88
89#include <dev/wscons/wsconsio.h>
90#include <dev/wscons/wseventvar.h>
91
92/*
93 * Initialize a wscons_event queue.
94 */
95void
96wsevent_init(struct wseventvar *ev)
97{
98
99	if (ev->q != NULL) {
100#ifdef DIAGNOSTIC
101		printf("wsevent_init: already initialized\n");
102#endif
103		return;
104	}
105	ev->get = ev->put = 0;
106	ev->q = malloc((u_long)WSEVENT_QSIZE * sizeof(struct wscons_event),
107	    M_DEVBUF, M_WAITOK);
108	bzero((caddr_t)ev->q, WSEVENT_QSIZE * sizeof(struct wscons_event));
109}
110
111/*
112 * Tear down a wscons_event queue.
113 */
114void
115wsevent_fini(struct wseventvar *ev)
116{
117	if (ev->q == NULL) {
118#ifdef DIAGNOSTIC
119		printf("wsevent_fini: already invoked\n");
120#endif
121		return;
122	}
123	free(ev->q, M_DEVBUF);
124	ev->q = NULL;
125}
126
127/*
128 * User-level interface: read, poll.
129 * (User cannot write an event queue.)
130 */
131int
132wsevent_read(struct wseventvar *ev, struct uio *uio, int flags)
133{
134	int s, n, cnt, error;
135
136	/*
137	 * Make sure we can return at least 1.
138	 */
139	if (uio->uio_resid < sizeof(struct wscons_event))
140		return (EMSGSIZE);	/* ??? */
141	s = splwsevent();
142	while (ev->get == ev->put) {
143		if (flags & IO_NDELAY) {
144			splx(s);
145			return (EWOULDBLOCK);
146		}
147		ev->wanted = 1;
148		error = tsleep(ev, PWSEVENT | PCATCH,
149		    "wsevent_read", 0);
150		if (error) {
151			splx(s);
152			return (error);
153		}
154	}
155	/*
156	 * Move wscons_event from tail end of queue (there is at least one
157	 * there).
158	 */
159	if (ev->put < ev->get)
160		cnt = WSEVENT_QSIZE - ev->get;	/* events in [get..QSIZE) */
161	else
162		cnt = ev->put - ev->get;	/* events in [get..put) */
163	splx(s);
164	n = howmany(uio->uio_resid, sizeof(struct wscons_event));
165	if (cnt > n)
166		cnt = n;
167	error = uiomove((caddr_t)&ev->q[ev->get],
168	    cnt * sizeof(struct wscons_event), uio);
169	n -= cnt;
170	/*
171	 * If we do not wrap to 0, used up all our space, or had an error,
172	 * stop.  Otherwise move from front of queue to put index, if there
173	 * is anything there to move.
174	 */
175	if ((ev->get = (ev->get + cnt) % WSEVENT_QSIZE) != 0 ||
176	    n == 0 || error || (cnt = ev->put) == 0)
177		return (error);
178	if (cnt > n)
179		cnt = n;
180	error = uiomove((caddr_t)&ev->q[0],
181	    cnt * sizeof(struct wscons_event), uio);
182	ev->get = cnt;
183	return (error);
184}
185
186int
187wsevent_poll(struct wseventvar *ev, int events, struct proc *p)
188{
189	int revents = 0;
190	int s = splwsevent();
191
192	if (events & (POLLIN | POLLRDNORM)) {
193		if (ev->get != ev->put)
194			revents |= events & (POLLIN | POLLRDNORM);
195		else
196			selrecord(p, &ev->sel);
197	}
198
199	splx(s);
200	return (revents);
201}
202